So I've been working on a pet project of mine outside of school- a cartoon accurate G1 Windcharger that transforms into a realistic version of his original toy (I'd say Masterpiece but I'm not confident I'd be able to model something *that* nice). Eventually I'd like to make a working prototype in PTC Creo/ProE that I can have 3D printed.

I'm finally at the point where I have some parts of the transformation finalized, but before I can even begin working this out, I realized I need to split the CAD model of the vehicle into the parts for transformation- right now I'd like to split the rear window and bumper into two sets of two pieces, but I'd have no idea at all how to go about doing that. I mean, I figure splitting the model up is the way to go, since every piece needs to line up when transforming between modes, but I have no idea how to go about doing it.

I was thinking I could solidify my model (which I need to do anyways) and then use extrusions to delete the parts I don't need, creating a new file, but I have no idea how I'd match up each surface after that point- there's no way I'd get the extrusions consistent every time if I'm working with a separate file every time.

If it's needed, I've attached a photo of what I'm working with right now- obviously still needs details like the head lamps and panel lines and the little bit on his hood, but it's definitely etched out enough to work with for now, especially now that I have the louvers on the rear window out of the way. If you guys need it to visualize what I'm talking about, splitting it into parts, just let me know and I can take a quick photo of my sketches.

Any and all help is appreciated- if any experts out there see anything wrong with my model, feel free to tell me, too! I only learned very basic solid modeling with Creo so creating this with all curves and surfaces was a very new experience I had to teach myself (in other words, I probably made tons of stupid mistakes).